Cell C will launch Wi-Fi calling by the end of July 2015, CEO Jose Dos Santos announced on 13 May.
This will allow subscribers to make voice calls over their home data network, and also while travelling overseas without incurring roaming charges.
Dos Santos said Wi-Fi calling is already available on a number of smartphones, and it just needs to finalise the last few details before launching the service.
Wi-Fi calling came back into the spotlight when the latest version of Apple’s mobile operating system, iOS 8, was set to support the feature.
In the United States, Wi-Fi calling has been available to Android users on T-Mobile for some time.
Services such as Skype, Google Hangouts, and Viber also offer the ability to make calls over a data network at lower prices than roaming offers.
These require you to sign up for an account, though, as well as recharge a separate account with airtime.